Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Ms. Janet S Hammer, PA-C
Physician Assistant in Boston, MA · enumerated 2007.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1124212204
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Registry record
Entity type Individual (Type 1)
Name Ms. Janet S Hammer
Credential PA-C
Sex Female
Practice address 110 Francis Street, Division of Infectious Disease, Suite Gb, Boston, MA, 02215
Phone (617) 632-7706
Fax (617) 632-7626
Enumeration date Aug 31, 2007
Last updated in NPPES Oct 31, 2016
Taxonomy & licenses
363A00000X Physician Assistant Physician Assistants & Advanced Practice Nursing Providers · License 294 (MA) Primary
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.
Frequently asked questions
What is the NPI number for Janet Hammer?
The National Provider Identifier (NPI) for Janet Hammer is 1124212204, a Type 1 (individual) record in the CMS NPPES registry.
Where does Janet Hammer practice?
The practice location on file with NPPES is in Boston, MA. Providers can have multiple locations; NPPES lists the primary practice address.
Other providers at this practice address
Browse all → Ron Alterman Neurological Surgery Physician · Boston, MA NPI 1750357430 Ajith Thomas Neurological Surgery Physician · Boston, MA NPI 1972525541 Mary Albrecht Infectious Disease Physician · Boston, MA NPI 1386737856 Katie Deary Nurse Practitioner · Boston, MA NPI 1801921275 Nicole Catatao Family Nurse Practitioner · Boston, MA NPI 1588830160 Vanessa Cowan Transplant Surgery Physician · Boston, MA NPI 1457592305 Julie Rocke Nurse Practitioner · Boston, MA NPI 1063725513 Ying-Sheng Lin Plastic Surgery Within the Head and Neck (Plastic Surgery) Physician · Boston, MA NPI 1942033709
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2016-10-31.